Not Applicable
The present invention relates generally to hand cleaners. More particularly, the present invention is directed to a hand cleaner comprising, inter alia, methyl soyate.
There has been a trend in the manufacture of personal care products to use ingredients that are environmentally safe and biodegradable. As a consequence, D-limonene, a terpene generally derived from the distilled rind oils of citrus fruits has become a popular constituent in hand cleaners, such as those manufactured under the trademarks DL, PERMATEX, FAST ORANGE by Loctite Corporation, Newington, Conn.
D-limonene is desirable as a cleaner in that it is a strong, biodegradable solvent. However, D-limonene has certain properties that are not desirable in a hand cleaner. Because D-limonene is a strong solvent, excess contact with the skin can cause drying, defatting and dermatitis of skin. In addition, the strong citrus odor of D-limonene competes with the scent of perfumes that may be added to impart other pleasant odors. In addition, D-limonene is not as environmentally friendly as once thought. The Environmental Protection Agency has identified D-limonene as a Volatile Organic Compound (VOC), which contributes to the formation of ozone.
It would be desirable to formulate a hand cleaner that is non-irritating to the skin, amenable to the addition of perfumes and environmentally friendly.
Accordant with the present invention, a formula for a hand cleaner that is non-irritating to the skin, amenable to the addition of perfumes and environmentally friendly surprisingly has been discovered. The hand cleaner comprises methyl soyate, a surfactant, an emulsifier, an emollient, a wetting agent, a pH-modifying agent, water, and optionally, fragrances, colorants, preservatives or aloe vera. The hand cleaner does not contain D-limonene. The inventive formulation is particularly useful for cleaning and conditioning a person""s hands.
The formulation according to the present inventor consists of a combination of methyl soyate, nonoxynol-9, PEG-75 lanolin, DMDM hydantoin, oleic acid, triethanolamine, aloe vera and water. The hand cleaner formulation does not contain D-limonene.
The inventive formula contains Methyl soyate in an amount of about 5 to about 50 percent by weight, based on the total weight of the formula. Methyl soyate is a methyl ester formed by reacting methanol with soybean oil in the presence of a catalyst. Methyl soyate is preferable to d-limonene as a solvent for a hand cleaner for several reasons. Methyl soyate is a milder solvent, and even prolonged contact with the skin is unlikely to cause drying, defatting and dermatitis of skin. To the contrary, the residue from a methyl soyate hand cleaner replenishes the skin with natural soy oil. Methyl soyate has a mild odor that will not interfere with most perfumes. Methyl soyate is not a VOC, and therefore more environmentally friendly that D-limonene.
Nonoxynol-9 is present as a non-ionic surfactant, acting as a wetting agent, detergent and emulsifier in the hand cleaner according to the present invention. In the preferred embodiment, the formula contains Nonoxynol-9 in amounts ranging from about 10 to about 14 weight percent, based on the total weight of the formula. Other surfactants that may be used instead in like amounts include, but are not limited to, sodium cocoyl isethionate, sodium dodecyl benzene sulfonate, sodium methyl oleoyl taurate, sodium lauryl sulfoacetate, sodium lauryl sulfate, sodium C.sub.14-16 olefin sulfonate, disodium lauryl sulfosuccinate, cocamidopropyl betaine, lauramide MEA, sucrose stearate, cetyl alcohol, laureth-3, polysorbate-85, sorbitan monolaurate, PEG-30 Castor Oil, PEG-6 cocamide, and distearyl dimethyl ammonium chloride.
Cocamide-DEA is present as an emulsifier. Preferably, the formula contains Cocamide-DEA in amounts ranging from about 4 to about 10 weight percent, based on the total weight of the formula. Alternatively, other alkylamides may be substituted for Cocamide-DEA in like amounts.
PEG-75 lanolin is present in the inventive formulation as an emollient and emulsifier. Preferably, the formula contains PEG-75 lanolin in amounts from about 0.50 to about 3.50 weight percent, based on the total weight of the formula. Other emollients that may be substituted for PEG-75 lanolin in like amounts include, but are not limited to, dimethicone, cyclomethicone, lanolin oil, lanolin fatty acid, lanolin alcohol, acetylated lanolin alcohol, acetylated alkoxylated lanolin such as laneth-9 acetate and laneth-10 acetate, alkoxylated lanolin having about 30 to about 75 moles of ethylene oxide or propylene oxide such as PEG-16 lanolin, PEG-27 lanolin, PEG-40 lanolin, PPG-12-PEG-50 lanolin, long chain esters such as cetyl acetate, stearyl acetate, oleyl acetate, lauryl lactate, myristyl lactate, cetyl lactate, stearyl lactate, decyl neopentanoate, decyl oleate, isopropyl myristate, lauryl myristate, myristyl myristate, myreth-3-myristate, palmityl myristate, stearyl myristate, isopropyl palmitate, octyl palmitate, 2-ethylhexyl palmitate, lauryl palmitate, myristyl palmitate, palmityl palmitate, stearyl palmitate, butyl stearate, myristyl stearate, palmityl stearate, isocetyl stearate, isostearyl isostearate, myristyl alcohol, cetyl alcohol, isocetyl alcohol, stearyl alcohol, oleyl alcohol, dioctyl succinate, didecyl succinate, caprylic/capric triglycerides, ethoxylated cholesterol, PEG-16 soya sterol, and mixtures thereof.
Triethanolamine is present in the inventive formulation as a wetting agent, to emulsify oily ingredients and increase their retention and absorption into the skin, thus acting as a moisturizer. Triethanolamine also acts as a neutralizer. Preferably, the formula contains triethanolamine in amounts from about 0.30 to about 1.30 weight percent, based on the total weight of the formula. Optionally, other alkaline neutralizers such as monoethanolamine may be substituted in like amounts. DMDM Hydantoin is a well-known preservative used in the present formulation. Other preservatives may be used. Preferably, the amount of DMDM Hydantoin is about 0.5 to about 2 weight percent, based on the total weight of the formula.
Oleic Acid is present in the inventive formulation to provide pH balance. Typically, the formula contains oleic acid in amounts from about 1.5 to about 4.5 weight percent, based on the total weight of the formula. The preferred pH is in the range of 5.0 to 8.0; more preferably, the pH is in the range of 6.5 to 7.5. Although Oleic Acid is used in the present formulation, other compounds such as benzoic acid, acetic acid, formic acid, citric acid, and phosphoric acid are also suitable and may be substituted for Oleic Acid in amounts necessary to produce a pH in the preferred range. Oleic Acid also acts as an anti-oxidant.
The hand cleaner herein described may optionally contain Aloe Vera, to protect the user""s hands when using the cleaning agent, and reduce the risk of any irritation to the user""s skin. By way of example, Aloe Vera gel can be added to the formula in amounts from zero to about 25 weight percent based on the total weight of the formula.
The hand cleaner herein described may optionally contain fragrance, in amounts from about zero to about 5 percent based on the total weight of the formula.
Water is added to the hand cleaner of the present invention to make up the balance of the weight of the hand cleaner, and may be provided in an amount from about 15% to about 25% by weight, based on the total weight of the formula.
The aforementioned ingredients may be combined and mixed in conventional high-shear mixing equipment, to form a hand cleaner, according to the present invention.